USING A WIZARD-OF-OZ TECHNIQUE TO EVALUATE CONNECTED VEHICLES: DISTRACTED DRIVER PERFORMANCE TO MULTIPLE ALERTS IN A MULTIPLECONFLICT SCENARIO

摘要

This paper presents insights gained from testing Connected-Vehicle Collision Avoidance System (CAS) applications using a Wizard-of-Oz technique. The study investigated whether CASs should present individual crash alerts in a multiple conflict scenario, or only present one alert in response to the first conflict and suppress subsequent alerts. Fifty-one participants followed a lead truck around a test-track while driving an instrumented vehicle. Once visually distracted, a trailing confederate vehicle repositioned itself into the participant vehicle’s blind spot and a cardboard box was also simultaneously dropped from the lead truck. Participants received a Forward Collision Warning (FCW) alert as the box landed on the road. Twenty six drivers swerved left in response to the box, encountering a lateral conflict with the adjacent confederate vehicle. Half of these drivers also received a Lane Change Warning (LCW) alert once they began to steer left. The FCW and LCW alerts were generated using the Wizard-of-Oz technique. It was found that drivers that received both the FCW and LCW alerts were significantly faster at steering away from the lateral crash threat than the drivers that only received the FCW alert (1.70 s vs. 2.76 s, respectively). Drivers liked receiving the LCW alert, rated it to be useful, found it easy to understand (despite being presented after the FCW alert), and did not find it to be startling. The results suggest that drivers that are familiar with CASs benefit from, and feel it is appropriate to generate, multiple alerts in a multiple conflict scenario. The results are expected to inform the design of CASs for connected vehicles. The methods devised in this study can also be used to evaluate connected vehicle and automated vehicle systems.